MICHAEL Jackson's death certificate has been released without a listed cause of death and a coroner said investigators are still testing the singer's brain. Public health officials issued the death certificate on Tuesday, the same day public and private memorials were held in Los Angeles. The cause of death is listed as “deferred.” Assistant Chief Coroner Ed Winter said Jackson's brain, or at least part of it, was still being held by investigators and would be returned to the family for interment once neuropathology tests were completed. “As soon as we are done with the brain, we will return it,” Winter said. “There is a whole series of tests that will be done.” It is not uncommon for the coroner to hold on to a brain or samples from it. Winter said families sometimes delay burying a loved one until after the brain has been returned, but he had received no word from the Jackson family about their intentions.